1. Technical Field of the Invention
The present invention relates to a type of copying apparatus wherein an electrostatic latent image formed on a photoconductive drum is developed by toner and also to a method for controlling development.
2. Brief Description of Related Art
When copying a book or two originals having uneven plane or a joint between pages or originals, there appears a shadow when exposure is made and it causes to produce black lines on an image.
Japanese Published Unexamined Utility Model Application No. 172854/1981 and No. 143632/1978 disclose original illuminating devices capable of solving such problems.
The devices are equipped with a main mirror which directs the light from a light source to one side of exposure portion of an original and a submirror which directs the light from the light source to opposite side of exposure portion of the original for illuminating the exposure portion of the original from both sides so as not to produce any shadow even if there exists uneven plane or a joint between two originals.
It may also be considered to erase a shadow portion which corresponds to a portion of a photoconductive drum by making use of a suberaser provided for erasing a portion other than a regular image since the portion where a shadow appears is known according to the size of each original when two originals are copied simultaneously.
Generally, however, low-cost copying machines are not equipped with such submirror and suberaser since a machine becomes considerably expensive when they are provided. Therefore, when two originals are copied simultaneously with such a low-cost copying machine, a shadow is produced between the originals, and the portion of shadow appears as black lines on an image copied.